HEALTH CHECK

It would be great if every MySQL database enjoyed perfect health 24 by 7, but unfortunately, trouble sometimes strikes. A logfile isn’t much help if you are investigating why a database is flooded with requests. Mtop to the rescue.

We looked at ApacheTop in this column not too long ago. ApacheTop is a tool that tells you what your web server is doing right now, pointing out potential bottlenecks. In this month’s column, we will be looking at another member of the top family: Mtop, the realtime monitor for MySQL [1]. The Mtop tarball weighs in at a mere 48 kbytes. It requires a few Perl modules: Curses, DBI, DBD::mysql, and Net::Domain – but you will probably have most of these installed anyway, and CPAN will fill any gaps in next to no time. After satisfying the dependencies, enter perl Makefile.PL, make, and make install in /usr/local/bin/ to complete the Mtop build. The next step is to allow Mtop access to your MySQL process information, as – in contrast to Apachetop – Mtop does not simply parse the server logfiles, but requires direct access. I decided to set up a user with extremely restricted privileges in MySQL and did not assign a password. The following SQL prompt should do the trick for version 4.0.2 or newer of MySQL: grant super, reload, U process on *.* to mysqltop; grant super, reload, U process on *.* to mysqltop@localhost; flush privileges;

Buy this article as PDF

Express-Checkout as PDF

Price $2.95(incl. VAT)

Buy Linux Magazine

Related content

Well-used services write reams of log information to disk, which is not only bothersome from a storage perspective but also pushes grep and the usual group of statistics tools to their limits. Will hitching the syslog daemon up to a database help?

Without TinyURL.com and similar URL shortening services, many Twitter postings would only have enough space left for “Look at this.” But if you run a web server yourself, you might prefer to grow your own shortener.

Just as a craftsman is unlikely to purchase a new angle grinder every month, sys admins are unlikely to change constantly their tried and trusted tools. Columnist Charly Kühnast ditches this conservative philosophy this month, lured by the charms of a new logfile tool.